package com.sjgs.common.ketama;

import com.sjgs.common.domain.Node;

import java.util.Collection;
import java.util.Iterator;
import java.util.List;

/**
 * Interface for locating a node by hash value.
 */
public interface NodeLocator {

  /**
   * Get the primary location for the given key.
   *
   * @param k the object key
   * @return the QueueAttachment containing the primary storage for a key
   */
  Node getPrimary(String k);

  /**
   * Get an iterator over the sequence of nodes that make up the backup
   * locations for a given key.
   *
   * @param k the object key
   * @return the sequence of backup nodes.
   */
  Iterator<Node> getSequence(String k);

  /**
   * Get all memcached nodes. This is useful for broadcasting messages.
   */
  Collection<Node> getAll();

  /**
   * Create a read-only copy of this NodeLocator.
   */
  NodeLocator getReadonlyCopy();

  /**
   * Update locator status.
   *
   * @param nodes New locator nodes.
   */
  void updateLocator(final List<Node> nodes);
}